In typewriters as they presently exist, whether they be electric powered or electronically controlled electric powered typewriters, when the operator causes the print point to move backward into the line of typing, for example, to correct an error or to remove an erroneous graphic from the page or to insert characters, the print carrier must be escaped rightward to the rightmost end of the print line before printing or typing may be resumed. Typically this is controlled by the operator by the use of functions such as tabulation and space. The use of the tabulation command necessitates the operator knowing exactly where the tabulation stops are located and the ability to then associate that location with the right most printed position on the typing line. This requires the operator to perform the operation consciously or alternatively to use the repeat space function and continue this operation through an extended period until the carrier has again assumed the desired position at the right most end of the typed material.
With the advent of proportional spacing typewriters and their increasing usage, the need to reposition the carrier very accurately is further necessitated and complicated by the fact that the characters in proportional spacing vary in width and therefore, the print point for the next character after the rightmost position of the typing line may well not correspond with a set or fixed character position. This will further compound the use of the tab and space routine described above since it will necessitate backspacing by one unit through one or more cycles to accurately place the carrier at the next character print point.
Even the routine of entering a tab stop prior to backing the carrier to the correction point will not work satisfactorily in the proportional spacing routine inasmuch as tab stops may only be set at predetermined character positions and cannot usually be set at individual escapement unit positions.
It is therefore an object of this invention to electronically control the carrier of a typewriter to place the print point immediately over the print point occupied at the rightmost position of the carrier in that particular writing line.
It is another object of this invention to control the print carrier to effect repositioning of the print point at the right most point in the typing line, by keyboard control.
It is still another object of this invention to simplify the demands on the operator in repositioning the carrier at the rightmost end of the writing line after the carrier has been positioned over a previous print point.